Combined sewing machine and trimmer blade



Nov. 11, 1952 N. DE ROBERTIS 2,617,374

COMBINED SEWING MACHINE AND TRIMMER BLADE Filed Jan. 25, 1951 2 SHEETS-SHEET 1 FIG. I.

INVENTOR. NICOL4 175' 20552715 ATTORNEYS 'Nov. 11, 1952 N. DE ROBERTIS 2,617,374

COMBINED SEWING MACHINE AND TRIMMER BLADE Filed Jan. 25, 1951 2 SHEETS-SHEET 2 v/coLA .DE ROBER TLS M I w I "M /w ATTOR NKYS Patented Nov. 11, 1952 COMBINED SEWING MACHINE AND TRIMMER BLADE Nicola De Robertis, New York, N. Y.

Application January25, 1951, Serial N0.'207,735

Claims.

My invention relates to a new and improved combined sewing machine and trimmer blade.

According to the invention, a simpleand eflicient attachment is provided, which can be easily attached or detached from the sewing machine and which can be easily coupled to or uncoupled from the drive of the sewing machine. The attachment may be applied to any type of machine or it may be used separately as a cutting device. By means of this attachment, the operation of the cutting or trimming blade can be stopped while the sewing machine sews a seam or the trimming blade can be operated simultaneously with the stitch-forming mechanism.

The apparatus is particularly useful in trimming the edges of pieces of fabric which constitute the work, during the sewing operation.

Without limitation thereto, the edges .of the pieces of fabric are trimmed while or immediately after the stitch is formed in the particular part of the work.

Numerous other objects and advantages and features of myinvention varedisclosed in the annexed description and drawings, which disclose a preferred embodiment.

Fig. 1 is a longitudinal elevation, partiallyin vertical section of the improved device and of certain conventional parts of a sewing machine. Some of these conventional parts are shown in broken lines;

Fig. 2 is an end elevation, taken at the left of Fig. 1;

Fig. 3 is a top plan view of Fig. 1; and

Figs. 4, 5 and 6 are respectively sections on the lines 44, 55 and 6-6 of Fig. 1.

Certain conventional parts of a sewing machine are shown in the drawing and the representation of many such conventional parts is omitted, as being unnecessary to explain this invention.

The machine has the usual table I, and bearings in which the usual rock shaft 2 is mounted. Thisshaft'z is oscillated to actuate the feed dog, which is not'shown. This rock shaft '2 is oscillated through a selected angle in the usual man-- ner. The hub of a rock arm-3 is fixed to the rock shaft 2 so that the rock arm 3 is oscillated in unison with the rock shaft 2. A vertically reciprocable driven'member or rod 5 is turnably connected by a detachable pivot 4 to the rock arm 3. This rod 5 extends through an opening 6 in the work supporting plate W. Said work supporting plate W is fixed to the top of the table l in' the usual manner.

A vertical and longitudinal plate 1 is integral 2 with a horizontal and longitudinal base 8. This plate constitutes a mount for other parts later described, and said mount may be of any type or .shape.

This base 8 is adjustably fixed to the top of the table l., so that plate 1 can-be adjusted longitudinally relative to table 1. For this purpose, the horizontal base 8 is provided with longitudinal slots oropenings-fi, and clamping screws I0 fix the horizontal and longitudinal base plate 8 in longitudinally adjusted ,position .to the top of the table 1.

As shown in Fig. l, a longitudinal and horizontal guide bar -I l 315 adjustably longitudinally fixed .to the vertical longitudinal plate 1. The .guide bar .H .is provided with a'longitudinal slot .or opening Ha and .-a-clamping screw l2 adjust- .ably fixes the bar II to the .plate 1, so that-bar .I Man he longitudinally adjusted. This bar II is integral with a transverse guide channel It, in which the head 5a of the driven member of rod .5 fits slidably to be guided in vertical and reciprocating sliding .movement. This head 5a is spaced transevrsely from the plate 1. The top of head 5a has a transverse and horizontal cylindrical guide recess.

A coupling pin 15 is transversely slidable in this recess relative to the head 5a. The cylindrical head l5a of coupling pin l 5 fits slidably in this recess of head 5a. An external head 15b is fixed to coupling pin 15. A compression spring l6 {urges the head l5ato'move transversely in a direction towards the plate 1. The plate 1 is provided with a vertical transverse recess, in which a longitudinal guide plate I! is fixed. As shown in Fig. '1, said guide plate I! is fixed to the plate '1 by screws or other fastening members A flange of the plate 1 extends behind the guide plate I! to provide a vertically disposed guide space. Aknife carriage 19 has a vertical longitudinal bar 20, which is vertically slidable betweenthe plates 1 and Win said vertical guide space,-in which the carriage-bar 20 fits slidably.

Said knife carriage I9 has a transverse finger piece 21a. for manipulating said knife carriage l9.

-Said'kni'fe carriage ['9 includes a vertical transverse bar 2| 'to which the upper and movable transverse knife K is fixed vertically adjustably by means of screws 22. The transverse carriagebar 2| is spaced longitudinally from the left or free edge of guide plate 1.

The upper movable .knife K cooperates with a lowerifixeditransverse linifeibar'23, which is'fixed to the work supporting plate W by means of screws 24. A transverse shearing cut is thus provided. This lower fixed knife bar 23 has a transverse cutting edge or knife 230, to make said shearing cut when the upper movable knife K is lowered. The knife carriage I9 is urged upwardly by means of a compression spring 25, which is located in a hollow and vertically disposed extension 26 of the fixed longitudinal plate 1. The knife carriage 19 has a transverse and rearwardly extending carriage-bar 26a which abuts the top end of the compression spring 25.

Said extension 26 has a top vertical slot or recess S in which bar 26a fits slidably.

The longitudinal carriage-bar 20 of the knife carriage I9 is provided with a transverse coupling hole 21. This hole 21 is equivalent to a recess.

Fig. 4 shows the knife K in its lowest operating position, into which knife K is moved while its carriage I9 is coupled to rock shaft 2. In order vertically to reciprocate the knife K, the coupling heat l5a of coupling pin is inserted into and kept in the transverse coupling hole 21 of the longitudinal carriage-bar of the knife carriage 19, as shown in Fig. 4. When the carriage bar 20 is thus connected to the driven head 5a, the knife K reciprocates vertically in unison with the vertical reciprocating movement of the needle N, thus trimming the work, while simultaneously sewing the seam or seams by means of the needle or needles and the auxiliary parts of the stitch-forming mechanism. Fig. 2 corresponds to Fig. 4, save that Fig. 2 shows the knife K in its top position to which it is moved while the carriage I9 is coupled to the head 5a.

Fig. 5 shows the head [5a disengaged from the opening 21, so that the knife K is held in its top non-operating position of Fig. 5 by spring 25, while the sewing machine operates to stitch the seam. In the position of Fig. 5, the spring 25 is uncompressed or the top of bar 26a may abut a stop.

In the position of Fig. 5, the coupling head l5a. abuts the vertical and smooth and imperforate wall of the carriage-bar 20 of the knife carriage I9. This wall thus serves as uncoupling means. When knife-carriage i9 is in its uncoupled position of Fig. 5, the smooth end of coupling head l5a slides along the adjacent unperforated part of the wall of longitudinal bar 20.

In order to operate the knife K, the sewing machine is temporarily stopped, and the knife carriage i9 is lowered from its position of Fig. 5 until the coupling head 15a enters the coupling perforation 21. Whenever desired, the knife carriage [9 can be uncoupled from the drive of the sewing machine, by merely pulling the coupling pin l5 outwardly by means of its head [5b. The spring 25 then automatically raises the knife carriage 19 in order to'uncouple the knife carriage H! from the driving mechanism of the sewing machine. Fig. 5 shows the top position of the upper knife K in broken lines. In this position, knife-carriage I9 is uncoupled from the drive.

In such position, the knife K is held elevated above the bottom of the adjacent part of the plate I and the plate IT. This provides a safety feature because the knife K is held sufficiently elevated so that it can not cut the finger of the operator, if such finger is accidentally moved under the plate ll.

Fig. 6 shows a pair of fabric sheet-s F and Fa which have irregular transversely disposed edges 30 and 30a which are to be trimmed. A guide 3| is provided in order to guide these irregular edges 30 and 38a in proper position under the vertically reciprocated upper knife K. This guide 3| has a transverse guide finger 32 for guiding edges 30 and 30a. Said guide 3| has a longitudinal slot 33. A clamping screw 34 adjustably connects the guide 3| to the horizontal base plate 8, so that the transverse guide finger 32 can be longitudinally adjusted.

Fig. 6 shows the smooth and trimmed edges 35 of the fabric pieces F and Fa and it shows the edge strip 36 which is out off as waste. Fig. 6 also shows the line of stitches 31 which are formed by the needle N and the other parts of the stitch-forming mechanism, while the work is being trimmed. Fig. 6 also shows the needle hole 38. This needle hole 38 is formed in the stationary knife bar 23.

Fig. 6 shows the selected width of the work between the trimmed edges 35 and the line of stitches 31. This selected width is determined by the width of the knife bar 23. For this purpose the knife bar 23 is easily removable and replaceable and the attachment has a suitable number of these bars 23. The width of the trimmed-off strip 36 is determined by the adjustment of the guide 3!. In order to permit the movement of the knife K to its bottom position when knife K is reciprocated, an additional plate 39 is fixed adiustably by a clamping screw 40 to the top of the table I. This plate 39 has a vertical recess 39a, which provides the necessary clearance for the movement of the knife K to its bottom position.

As shown in Fig. 4, the movable knife K is provided with a cutting edge C and with a supplemental cutting edge Ca. This short supplemental cutting edge Ca is provided on an extension 4| of the knife K.

When the knife K is in its top operating position of Fig. 2, the extension Ca is slightly below the top of the fixed cutting blade 23a of the knife bar 23. Therefore, when the knife K is lowered from its top operating position of Fig. 2 to its bottom position of Fig. 4, the extension Ca acts as a guide in order to insure accurate cutting registration.

As shown in Figs. 1 and 2, the cutting edge 23a is integral with the knife bar 23 and such knife bgr 23 is of increased height at its cutting edge 2 a.

In effect, the plate I! is a part of plate 1.

In order to assemble the parts, the driven member 5 is inserted in channel 14 at the outer face of plate 1, so that driven member 5 extends through the opening 6 of the work-supporting plate W. The heel of arm 3 is fixed to rockshaft 2, and pivot 4 is inserted at the junction of driven member 5 and arm 3. The channel [4 prevents any transverse movement of head 5a relative to plate 1.

The spring 25 is then inserted into recess 26 and carriage-bar 20 is then inserted between plate I! and 1, while the coupling pin I5 is held in its outer uncoupling position. The carriagebar 20 is thus assembled with plate "I in either of the positions shown in Figs. 2 and 5. The knife K can be assembled with knife-carriage I9, before or after knife-carriage I9 is assembled with plate 1.

The knife-bar 23 is fixed to work-supporting plate W before or after the assembly of the driven member 5 and knife-carriage IS with plate I.

Theparts are thus easily assembled with or removed from the sewing machine or other machine to which the attachment is applied. For convenience, channel guide I4 is designated as a first guide for the movable or driven member 5, and the space between plates 1 and H is designated as a second guide.

I have disclosed a preferred embodiment of my invention, but numerous changes and omissions and additions and substitutions can be made without departing from its scope. This includes the sub-combinations of the complete combination disclosed herein.

I claim:

1. A trimming attachment for sewing machines comprising a vertical mounting plate of planar type having a base flange positioned on the machine table top for adjustment toward and from the sewing line, a vertically oscillable power means extending through the table top and having a head zone opposite but spaced from said plate, said head zone being oscillable with said means, a knife carrier positioned for vertical movement on and relative to said mounting plate, said carrier being spring supported and having a wall movable vertically within a vertical guide space of said mounting plate with the wall including an opening, said carrier having means for mounting the movable knife blade for vertical adjustment, a spring supported plunger carried by said head zone means adapted for engagement at will with the carrier wall opening to thereby subject the carrier to the oscillation of the means. said plunger being freely movable on said carrier Wall when disengaged from the opening, said carrier moving to inactive position by spring action when the plunger is disengaged, said carrier having manually operative means for moving the carrier to position such wall opening in alinement with the plunger to thereby operatively connect the carrier with the oscillable means, a complemental knife member carried by the table top for cooperation with the carrier knife, said member having an upstanding zone, and a guide carried by the table top above the mounting plate flange and adjustable toward and from the sewing line for cooperation with the edge of the material in controlling the material movement relative to the cutting line of the reciprocating knife during activity of the latter, the

supporting spring for the carrier being positioned at the side of the mounting plate opposite the position of the plunger with the carrier manually controlled means positioned on the same side of such plate as the plunger.

2. An attachment as in claim 1 characterized in that the complemental knife member is removably mounted to permit substitution of members difiering as to the relative positions of the cutting edge and the needle hole to thereby permit variation in the width of the seam selvage by selection of the proper complementary member cooperative with the position of the reciprocating knife provided by the adjustment of the mounting plate.

3. An attachment as in claim 1 characterized in that the casing for the carrier spring projects above the top plane of the mounting plate and is semi-circular in cross section, is open-topped, and provided with a vertical slot leading downward from such open top, said carrier having a laterally extending arm in the plane of the manually controlled means with the arm extending in overlying relation to such carrier supporting spring and into said vertical slot to thereby permit movement of the carrier between its active and inactive positions.

4. An attachment as in claim 1 characterized in that the mounting plate carries an element cooperative with the head zone of the oscillable means for controlling the position of the latter relative to the cutting plane, said element being adjustably mounted on the plate.

5. An attachment as in claim 1 characterized in that the guiding space for the knife carrier is formed in an end zone of the mounting plate and extends parallel with the plane of the plate face, said carrier having an angular extension forwardly beyond the space to thereby provide the seating face for the removable knife with the plane of the latter extending at right angles to the plane of the mounting plate face.

NICOLA DE ROBERTIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 985,115 Kohn Feb. 21, 1911 1,940,501 McCann Dec. 19, 1933 1,994,385 Chudner Mar. 12, 1935 2,538,271 Reimer Jan. 16, 

